In the use of liquid developer such as aqueous ammonia for developing exposed diazotype copy sheets, in order to obtain images of high quality it is necessary that the flow rate of the aqueous ammonia be accurately dispensed in controlled metered quantities to a developer system of the copy machine. Thus, to determine the flow rate and adjust the flow as required necessitates measuring the quantity of ammonia being dispensed.
Conventionally, such measuring of the ammonia flow rate requires disconnecting an end of a feed tube, which conveys the aqueous ammonia from a dispensing means to the developer system, from the dispensing means, receiving the ammonia being dispensed in a hand-held open measuring tube and timing the quantity of ammonia supplied to the measuring tube during a predetermined time duration. Since the measuring operation often occurs near or at eye-level, the person performing the operation is subject to an unnecessary hazard of exposure to the volatile aqueous ammonia.